Solid formulation

ABSTRACT

A water dispersible solid formulation comprising an active ingredient, a surfactant of non-ionic type, a surfactant of anionic type and at least 30 wt % of urea is disclosed. A process of preparing the formulation and the use of the formulation for delivering an active ingredient, for example a pesticide or plant growth regulant to an agricultural or horticultural locus are also described.

The present invention relates to a solid formulation and particularly,although not exclusively, relates to crop protection formulations whichare in solid form, for example, powder, granules or tablets.

Crop protection agents are formulated in solid or liquid compositions,usually in the form of a concentrate for ease of handling andtransportation, which are diluted with water by the user beforeapplication.

Since unsophisticated mixing techniques are often used for dilutingsolid formulations, one important requirement .for such formulations isthat of rapid dispersal in water. If a solid formulation does notdisperse rapidly, clogging of spray equipment with undispersedformulation may occur and, furthermore, there may be inadequateapplication of active ingredient to the crop to be treated.

Many known processes for the preparation of solid crop protectionformulations require the active ingredient to be pre-milled to a fineparticle size and/or require a drying step, in order to remove water andform a solid. Such process steps add to the inefficiency of the overallprocess.

The patent literature discloses many solid crop protection formulations.For example, U.S. Pat. No. 3,274,052 (FMC) discloses a process for thepreparation of pesticide granules which comprises the step of coatingthe surface of granular carrier particles with an active ingredient. Thegranular carrier particles may be any water-insoluble or water soluble,porous or non-porous material. Examples of water soluble materialsdisclosed include fertilisers such as ammonium phosphate, ammoniumsulphate, urea, murkate of potash and super-phosphate.

French Patent Application No. 2 645 709 (Sumitomo) discloses a processfor the preparation of an emulsifiable solid pesticidal compositionwhich comprises melting a pesticide and a water soluble polymer, forexample, polyethylene glycol, a surfactant, a solvent and/or a watersoluble support. Examples of water soluble supports disclosed includehydropropylcellulose, urea, lactose and ammonium sulphate.

PCT Patent Application Number WO 91/13546 (DuPont) discloseswater-dispersible or water-soluble pesticide granules which comprise 5%to 95% of pesticidal particles in combination with 5% to 40% of awater-soluble heat activated binder (HAB). Examples of HABs disclosedinclude ethylene oxide/propylene oxide copolymers and polyethoxylateddinonylphenol. The HABs may also include up to 50% co-binders such aspolyethylene glycols, polyethylene oxide, polyethoxylated fatty acids oralcohols, hydrated inorganics such as sodium silicate, sorbital or urea.

Barker and Renauto disclosed urea adducts of non-ionic surface activeagents in The Journal of the American Oil Chemist's Society, volume 32,May 1955 at page 249 et seq. The disclosure indicates that "otheringredients, such as perfumes, dyes, gums, alkaline builders,insecticides, germicides and solvents, may be added during the mixing ormilling operation". It is believed that the mixture of ureaadduct/insecticides proposed was a scatter formulation which wasintended to be used in solid form.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 to 5 graphically show the particle size in the ordinate, as afunction of the water content in the abscissa, respectively for theformulations in Examples 7 to 11.

This invention is based upon the discovery of a novel solid formulationwhich may rapidly be dispersed in water.

According to a first aspect of the present invention, there is provideda water dispersible solid formulation comprising:

an active ingredient;

a surfactant of a non-ionic type;

a surfactant of an anionic type; and

at least 30 wt % of urea.

Such a formulation has, surprisingly, been found to disperse rapidly inwater.

In the context of this specification, the term "active ingredient" (orsimilar term) includes, within its scope, pesticides, for example,insecticides, fungicides, acaricides, ovicides, nematocides andherbicides, and plant growth regulators.

Said urea is preferably complexed with at least one of the otheringredients of the formulation. Said urea and at least one otheringredient are preferably in the form of an inclusion complex, forexample a canal complex.

In an inclusion complex, two compounds are associated with one anothersuch that one compound (hereinafter the "guest compound") is eitherwholly or partly locked within the crystal lattice of the othercompound. In a canal complex, tunnels are defined by one compound, withthe guest compound being wholly or partly located. Within the tunnels.In a canal complex of urea, the urea defines tunnels in which moleculesof guest compound are located.

Preferably, urea is complexed with said surfactant of non-ionic type.

Said solid formulation may include at least 40wt % of urea. Preferably,said solid formulation includes at least 45 wt % of urea. Morepreferably, said solid formulation includes at least 50. wt % of urea.Said solid formulation preferably includes no more than 70 wt % of urea.

Preferably, the ratio of urea to guest compound(s) is in the range 70:30to 50:50.

Preferably, said urea is dispersed, suitably in a random fashion,throughout said solid formulation.

Said surfactant of non-ionic type preferably has predominantly non-ionicproperties.

Said surfactant of non-ionic type is preferably an adjuvant. Suchsurfactants are normally available in the form of a mixture. Saidsurfactant of non-ionic type preferably predominantly includes aliphatichydrocarbon moieties. Said aliphatic hydrocarbon moieties may bepredominantly linear or branched. Preferably, linear hydrocarbonmoieties predominate in said surfactant of non-ionic type.

In the context of this specification, the .terms "predominate" and"predominantly" denote "more then 50 wt %" and, preferably, "more than80 wt %".

Preferably, said surfactant of non-ionic type predominantly includeshydrocarbon moieties having at least 8 carbon atoms and, morepreferably, having at least 10 carbon atoms. In the most preferredembodiment, said surfactant of non-ionic type predominantly includeshydrocarbon moieties having at least 12 carbon atoms.

The molecular weight of said surfactant of non-ionic type is preferablygreater than 300 and, more preferably, within the range 350-20000.

Said surfactant of non-ionic type may be selected from alcohols(preferably fatty alcohols), esters (preferably fatty esters), andalkoxylated alcohols and esters.

Preferred surfactants of non-ionic type include polyethylene glycol,alkoxylated fatty alcohol and alkoxylated nonylphenol.

Where said surfactant of non-ionic type is alkoxylated, it is preferablyethoxylated and, preferably, includes on average less than 20, morepreferably, less than 15, ethylene oxide units per molecule.

Said surfactant of non-ionic type preferably comprises at least 10 wt %of the solid formulation. Preferably said surfactant of non-ionic typecomprises 10-40 wt %, more preferably 10-30 wt %, of the solidformulation.

Preferably, said surfactant of non-ionic type is of low hygroscopicity.At equilibrium, at 21° C. in air of 75% relative humidity, saidsurfactant of non-ionic type preferably takes up less than 25 g, morepreferably, less than 20 g, of moisture per 100 g of the dry material.At equilibrium, at 21° C. in air of 32% relative humidity, saidsurfactant of non-ionic type preferably takes up less than 10 g, morepreferably less than 5 g, of moisture per 100 g of the dry material.

Said surfactant of anionic type preferably has predominantly anionicproperties. Preferred surfactants of anionic type include Morwet D425(Trade Mark for a sodium salt of a sulphonated naphthalene/formaldehydecondensate), Empicol LZ (Trade Mark for sodium lauryl sulphate) andNansa HS 85 (Trade Mark for sodium dodecylbenzene sulphonate).

Said surfactant of anionic type is preferably dispersed, suitably in arandom fashion, throughout said solid formulation.

Preferably, said surfactant of anionic type comprises at least 4 wt % ofthe solid formulation. Preferably, said surfactant of anionic typecomprises 4-30 wt %, more preferably 4-15 wt %, of the solidformulation. Preferably, the amount of surfactant of anionic type insaid solid formulation is less than the amount of surfactant ofnon-ionic type in said formulation, weight for weight.

Preferably, said surfactant of anionic type is of low hygroscopicity. Atequilibrium, at 21° C. in air of 75% relative humidity, said surfactantof anionic type preferably takes up less than 30 g, more preferably lessthan 25 g, of moisture per 100 g of the dry material. At equilibrium, at21° C. in air of 32% relative humidity, said surfactant of anionic typepreferably takes up less than 10 g, more preferably less than 5 g, ofmoisture per 100 g of the dry material.

Said active ingredient preferably comprises at least 5 wt % of the solidformulation. Preferably, said active pesticidal ingredient comprises10-40 wt %, more preferably 10-20 wt %, of the solid formulation.

The melting point of said active ingredient may be at least 35° C. Themelting point of said active ingredient is preferably in the range 35°C. to 95° C.

The solubility in water at 25° C. of said active ingredient may be lessthan 10,000 ppm and is preferably less than 1,000 ppm. The solubility inwater at 25° C. of said active ingredient is preferably at least 1 ppmand is, more preferably, at least 10 ppm. It has, surprisingly, beenfound that a solid formulation which includes an active ingredient oflow solubility in water does, in fact, disperse relatively rapidly inwater.

A preferred active ingredient is triazamate ethyl(3-tertbutyl-1-dimethylcarbamoyl-1H-1,2,4-triazol-5-ylthio)acetate!. Itis believed that the following active ingredients may alsoadvantageously be provided in a solid formulation in accordance with-the present invention:

Alachlor 2-chloro-2', 6'-diethyl-N-methoxymethylacetanilide!, Aldicarb2-methyl-2-(methylthio)propionaldehyde O-methylcarbamoyloxime!,Alpha-cypermethrin a racemate comprising(S)-α-cyano-3-phenoxybenzyl(1R)-cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylateand(R)-α-cyano-3-phenoxybenzyl(1S)-cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate!,amitraz N,N-bis(2,4-xylyliminomethyl)methylamine!, cymoxanil1-(2-cyano-2-methyoxyiminoacetyl)-3-ethylurea!, dimethomorph 4-3-(4-chlorophenyl)-3-(3,4-dimethoxyphenyl)acryloyl!morpholine (Z to Eratio normally 4:1)!, flamprop-M IsopropylN-benzoyl-N-(3-chloro-4-fluorophenyl)-D-alaninate and the correspondingmethyl ester!, flurenol-butyl butyl ester of9-hydroxyfluorene-9-carboxylic acid!, flusilazolebis(4-fluorophenyl)(methyl) (1H-1,2,4-triazol-1-ylmethyl)silane!,pirimicarb 2-dimethylamino-5,6-dimethylpyrimidin-4-yldimethylcarbamate!, propoxur 2-isopropoxyphenyl methylcarbamate!, andtetrachlorvinphos (2)-2-chloro-l-(2,4,5-trichlorophenyl)vinyl dimethylphosphate!.

Said active ingredient is preferably dispersed, suitably in a randomfashion, throughout said solid formulation.

The average particle size by volume of said active ingredient in saidsolid formulation may be less than 50 μm, is preferably less than 25 μmand, more preferably, is less than 10μm.

The solid formulation may include one or a plurality of different activeingredients.

Said water dispersible solid formulation preferably includes less than 2wt %, more preferably less than 1 wt %, of water.

Said water dispersible solid formulation may include a small amount ofan acid, for example phosphoric acid or maleic acid. Preferably, saidwater dispersible solid formulation includes less than 5 wt % and, morepreferably, less than 2 wt % of said acid.

Said water dispersible solid formulation may include a defoamer. In thiscase, less than 5 wt %, preferably less than 1 wt %, of said defoamermay be provided in the formulation.

Said water dispersible solid formulation may include up to 20 wt % of afinely divided mineral filler, for example gypsum, kaolinite, talc,bentonite, synthetic alumina silicates, colloidal alumina and colloidalsilica.

Said water dispersible solid formulation may include a hydrocarbon whichis preferably an adjuvant. Said hydrocarbon is preferably a straightchain hydrocarbon (preferably C₁₂ to C₂₄). Said hydrocarbon may compriseless than 20 wt %, preferably less than 15 wt % and, more preferablyless than 10 wt % of the solid formulation. Where a hydrocarbon isprovided, said surfactant of non-ionic type is preferably an emulsifierfor the hydrocarbon when in water.

1 g of said water dispersible solid formulation preferably dispersesfully in 100 ml of distilled water at 21° C. within 5 minutes,preferably within 2 minutes and, more preferably, within 1 minute.

According to a second aspect of the present invention, there is provideda process of preparing a water dispersible solid formulation of saidfirst aspect, the process comprising mixing together an activeingredient, a surfactant of a non-ionic type, a surfactant of an anionictype and at least 30 wt % of urea and allowing the mixture to solidify.

The ingredients used in said process may be as described in anystatement herein.

The process is preferably carried out under conditions which cause saidurea to form an inclusion complex with one or more of the otheringredients.

Preferably, the active ingredient, the surfactant of non-ionic type andthe surfactant of anionic type are mixed together, suitably at anelevated temperature, preferably in the range 30° C. to 90° C. Asubstantially homogenous mixture is preferably produced. Said urea ispreferably then added to the mixture, suitably with mixing and at anelevated temperature, preferably within the range 30° C. to 90° C., morepreferably within the range 30° C. to 45° C.

Preferably, in the process, one or more of the ingredients is caused tomelt. Preferably, said surfactant of non-ionic type and/or said activeingredient is/are caused to melt. In a preferred embodiment, said activeingredient and said surfactant of non-ionic type are melted togetherwith mixing at an elevated temperature, suitably to produce asubstantially homogenous mixture. Said surfactant of anionic type ispreferably then added with mixing, the mixture being maintained at anelevated temperature. The urea is preferably then added to the mixture,suitably with mixing. The mixture is then preferably allowed to cool toambient temperature and allowed to stand for a period of time.

It has been found that, in the abovedescribed process, the activeingredient can form a fine solid particulate precipitate within thesolid formulation.

In view of the steps in the abovedescribed process of initially meltingthe active ingredient and then allowing the active ingredient toprecipitate, it may, advantageously not be necessary to mill (orotherwise process) the active ingredient prior to the preparation of thesolid formulation.

Preferably, the process is carried out in the presence of a minor amountof water. Water is suitably added in the process prior to the additionof urea.

It has been found that the amount of water present in the processaffects the particle size of the active ingredient in the solidformulation and the dispersibility of the solid formulation. Preferably,the process is carried out in the presence of at least 1 wt % of waterand, more preferably, in the presence of at least 2 wt % of water.Preferably, the process is carried out in the presence of less than 10wt % of water and, more preferably, in the presence of less than 5 wt %of water.

Preferably, the process is carried out in the presence of a minor amountof an acid. Said acid is suitably added in the process prior to theaddition of urea.

The product of the abovedescribed process is preferably dried or allowedto dry and may then be milled in order to produce a fine powder orformed into pellets or granules.

According to a third aspect of the present invention, there is provideda water dispersible solid formulation when prepared by the process ofthe second aspect.

According to a fourth aspect of the present invention, there is provideda method of delivering an active ingredient to a locus, the methodcomprising applying to the locus an aqueous dispersion of the waterdispersible solid formulation of said first or said third aspects.

In the method, the locus may be an agricultural or horticultural locus.

Said method is preferably a method of combatting pests, for exampleaphid pests.

Said water dispersible solid formulation preferably comprises 0.1 to 50g/kg, more preferably 0.25 to 20 g/kg of said aqueous dispersion.

According to a fifth aspect of the present invention, there is providedthe use of a water dispersible solid formulation of said first or thirdaspects for the preparation of an aqueous dispersion for delivering anactive ingredient to a locus.

Preferably, said locus is an agricultural or horticultural locus.Preferably, the use is for combatting pests.

The invention will now be described with reference to the followingexamples.

Examples 1 and 2 and Comparative Examples C1 and C2 show the effect ondispersibility of the solid formulations of including an anionicsurfactant in the formulations.

Examples 3 to 6 and Comparative Example C3 illustrate the effect ondispersibility and active ingredient particle size of including ananionic surfactant in the formulations.

Examples 7 to 11 illustrate the effect on dispersibility of varying thequantity of water used in the processes of preparation of theformulations.

The chemicals described below are referred to in the Examples by acommon name or trade name.

Triazamate (i.e.ethyl(3-tertbutyl-1-dimethylcarbamoyl-1H-1,2,4-triazol-5-ylthio)acetate) --sold under the Trade Mark AZTEC (outside U.S.A. ) by ShellInternational Chemical Company Limited. --an aphicide.

Triton X-100 (Trade Mark)--octylphenol ethoxylate with 9-10 ethyleneoxide units, supplied by Rohm & Haas--a non-ionic adjuvant.

Morwet D425 (Trade Mark)--a sodium salt of a sulphonatednaphthalene/formaldehyde condensate, supplied by Witco--an anionicsurfactant.

PEG 6000 and PEG 400 --polyethylene glycol of average molecular weightof 6000 and 400 respectively--a non-ionic adjuvant.

Hoe S4004 (Trade Mark)--a natural alcohol ethoxylate containing 7ethylene oxide units, supplied by Hoechst--a non-ionic adjuvant.

Genapol C100 (Trade Mark)--a coconut alcohol having 10 ethylene oxideUnits, supplied by Hoechst--a non-ionic adjuvant. Arkopal N110 (TradeMark)--a nonylphenol ethoxylate with 11 ethylene oxide units--anon-ionic surfactant.

Nansa HS 85 (Trade Mark)--sodium dodecylbenzene. sulphonate, supplied byAlbright and Wilson--an anionic surfactant.

Empicol LZ (Trade Mark)--sodium lauryl sulphate, supplied by Albrightand Wilson--an anionic surfactant.

The ingredients of the formulations of Examples 1, 2 and ComparativeExamples C1, C2 are shown in Table 1. Details on the processes for thepreparation of the formulation of the Examples are provided below.Example 1, 2, C1 and C2 were each prepared on a 50 g scale.

EXAMPLE 1

Triazamate and Triton XT100 were weighed into a suitable screw-cappedjar in a fume cupboard. The jar was then capped and stored in alaboratory oven at 70° to 80° C. with swirling until the triazamate andTriton X-100 had melted together to form a mixture. Morwet D425 was thenadded and heated with the mixture for between 20 and 30 minutes. Themixture was then stirred thoroughly. Subsequently, urea was added to themixture at ambient temperature.

Observations

After addition of urea, the mixture was a viscous dark brown paste.After 75 minutes standing at ambient temperature, the mixture becamehard but not brittle. After 16 hours standing, the mixture became ahard, sticky, unstirrable paste.

EXAMPLE 2

The process of Example 1 was followed, with phenylsulphonate being addedinstead of Morwet D425.

Observations

After addition of urea, a viscous, but easily stirrable, paste resultedwhich had not hardened after 75 minutes standing at ambient temperature.After standing at ambient temperature overnight, the mixture remained asa softish greasy gel.

COMPARATIVE EXAMPLE C1

Triazamate was added to a hot solution of PEG 6000 in Triton X-100 anddissolved by heating and swirling. The urea (at ambient temperature) wasthen stirred into the solution without delay.

Observations

The mixture was relatively viscous after standing for about one minuteat ambient temperature. After standing overnight, the mixture becamehard, but not brittle.

COMPARATIVE EXAMPLE C2

Triazamate and-Triton X-100 were melted together at 60° to 65° C. toform a mixture. The urea (at ambient temperature) was added withoutdelay and with stirring.

Observations

After 90 minutes standing at ambient temperature the mixture was aviscous paste. After standing overnight, the mixture became a waxy,non-comminutable gel.

                                      TABLE 1                                     __________________________________________________________________________    WEIGHT % ADDED                                                                                       PHENYL-                                                EXAMPLE     TRITON                                                                             MORWET                                                                              SULPHONATE                                                                            PEG                                            NO.   Triazamate                                                                          X-100                                                                              D425  Ca      6000                                                                             UREA                                        __________________________________________________________________________    1     14.6  14.0 14.0  --      -- 57.4                                        2     14.6  28.6 --    4.0     -- 52.8                                        C1    14.8  15.0 --    --      14.0                                                                             56.2                                        C2    14.6  28.6 --    --      -- 56.8                                        __________________________________________________________________________

EXAMPLES 3 TO 6 AND COMPARATIVE EXAMPLE C3

The ingredients of the formulations of Examples 3 to 6 and ComparativeExample C3 are shown in Table 2. Each formulation was prepared accordingto the general process described below.

Triazamate and Hoe S4004 were weighed into a suitable screw-capped jar(60-500 g capacity) in a fume cupboard. The jar was capped and thenstored in a laboratory oven at 65° to 75° C. until the triazamate andHoe S4004 had melted. Subsequently, the melt was stirred or swirledgently in the jar to homogenise it. With the jar placed on a pan of anelectronic balance, all other ingredients of the formulation (with theexception of urea) were then weighed in immediately. The most usualorder of addition was (1) phosphoric acid; (2) Morwet D425 (if added);and (3) water. After mixing the ingredients, as far as possible, byswirling, the closed jar was placed in an oven at 60°-70° C. After 35-45minutes standing, the mixture was allowed to cool with stirring to40°-42° C. Temperature was monitored continuously using a EurisemTechnics (Trade Mark) electronic thermometer fitted with a "K" Type 622(Trade Mark) probe. The jar was then opened and the urea added andincorporated into the mixture without delay by stirring for a fewminutes with a metal spatula or rod. The jar was then closed and allowedto stand at ambient temperature for at least 16 hours. During thisperiod, the triazamate was precipitated in a solid particulate form.

The products of the above process which were generally fudge-like masseswere transferred to open dishes or trays in which they were allowed todry to constant weight at ambient temperature either in a vacuum oven,or in a fume cupboard. The dried masses thus obtained were, if hardenough, converted to a coarse powder by milling for 5 to 10 seconds in asmall coffee mill which was operated in a fume cupboard. The powderformed was then screened on a BS16 mesh sieve (1 mm apertures). Anyoversize powder was re-milled until it could pass the same sieve.

                                      TABLE 2                                     __________________________________________________________________________    WEIGHT % ADDED                                                                                       PHOS-                                                  EXAMPLE     Hoe  MORWET                                                                              PHORIC                                                 NO.   Triazamate                                                                          S4004                                                                              D425  ACID WATER                                                                              UREA                                         __________________________________________________________________________    3     14.0  24.0 4.0   0.5  3.0  54.5                                         4     14.0  21.0 7.0   0.5  3.0  54.5                                         5     14.0  18.0 10.0  0.5  3.0  54.5                                         6     14.0  15.0 13.0  0.5  3.0  54.5                                         C3    14.0  28.0 --    0.5  3.0  54.5                                         __________________________________________________________________________

EXAMPLE 7

By processes analogous to those described above, various formulationswere prepared using the following ingredients:

    ______________________________________                                        Ingredient    Weight % added                                                  ______________________________________                                        Triazamate    14.0                                                            PEG 400       14.0                                                            Morwet D425   13.0                                                            Water         0-10                                                            Urea          balance up to 100                                               ______________________________________                                    

It will be appreciated that, in this example, the weight percent oftriazamate, PEG 400 and Morwet D425 added to the various formulationsremains constant, but the weight percent of water added in the processis varied, with urea making up the balance.

EXAMPLE 8

By processes analogous to those described above, various formulationswere prepared using the following ingredients:

    ______________________________________                                        Ingredient     Weight % added                                                 ______________________________________                                        Triazamate     14.0                                                           Genapol C100   14.0                                                           Morwet D425    13.0                                                           Phosphoric acid                                                                               0.5                                                           Water          0-6.0                                                          Urea           balance up to 100                                              ______________________________________                                    

As in Example 7, the weight percent of water added is varied, with ureamaking up the balance.

EXAMPLE 9

By processes analogous to those described above, various formulationswere prepared using the following ingredients:

    ______________________________________                                        Ingredient     Weight % added                                                 ______________________________________                                        Triazamate     14.0                                                           Arkopal N110   14.0                                                           Morwet D425    13.0                                                           Water          0 to 4.0                                                       Phosphoric acid                                                                               0.5                                                           Urea           balance up to 100                                              ______________________________________                                    

As in Example 7, the weight percent of water added is varied, with ureamaking up the balance.

EXAMPLE 10

By processes analogous to those described above, various formulationswere prepared using the following ingredients:

    ______________________________________                                        Ingredient     Weight % added                                                 ______________________________________                                        Triazamate     14.0                                                           Genapol C100   14.0                                                           Nansa HS 85    13.0                                                           Phosphoric acid                                                                               0.25                                                          Water          0 to 3.0                                                       Urea           balance up to 100                                              ______________________________________                                    

As in Example 7, the weight percent of water added is varied, with ureamaking up the balance.

EXAMPLE 11

By processes analogous to those described above, various formulationswere prepared using the following ingredients:

    ______________________________________                                        Ingredient    Weight % added                                                  ______________________________________                                        Triazamate    14.0                                                            Hoe S4004     14.0                                                            Empicol LZ    13.0                                                            Maleic acid    0.2                                                            Defoamer SF    1.0                                                            Water         0-2.0                                                           Urea          balance up to 100                                               ______________________________________                                    

As in Example 7, the weight percent of water added is varied, with ureamaking up the balance. (It should be noted that Defoamer SF itselfincludes 93% water).

EXAMPLE 12 Dispersibility of the Formulations in Water

Dispersibility of the formulations of Examples 1 to 11 and ComparativeExamples C1 to C3 was examined in a simple procedure which involved theaddition of 100 ml of distilled water to 1.00 g of the formulations in a250 ml beaker followed by occasional gentle swirling. No particular carewas taken with the form, e.g. coarse or fine, in which the formulationswere added to the water, unless otherwise stated.

Details concerning the dispersibility of the formulations are noted inTable 3 below.

                  TABLE 3                                                         ______________________________________                                        EXAMPLE NO:      DISPERSIBILITY                                               ______________________________________                                        1                Lumps up to 8 mm in size                                                      dispersed completely                                                          within 9 minutes                                             2                Lumps up to 8 mm in size                                                      dispersed completely                                                          within 24 to 25 minutes                                      3                Granules up to 1 mm in size                                                   dispersed completely                                                          within 1.5 to 2 minutes                                      4                Granules up to 1 mm in size                                                   dispersed completely                                                          within 60 to 70 seconds                                      5                Granules up to 1 mm in size                                                   dispersed completely                                                          within 45 to 60 seconds                                      6                Granules up to 1 mm in size                                                   dispersed completely                                                          within 45 seconds                                            7                Lumps up to 8 mm in size                                                      dispersed in circa 3                                                          minutes when prepared                                                         using greater than 2.5%                                                       water                                                        8                Lumps up to 8 mm in size                                                      dispersed completely in                                                       less than 11 minutes when                                                     prepared using greater                                                        than 2.5% water                                              9                Lumps up to 8 mm in size                                                      dispersed in less than 5                                                      minutes when prepared                                                         using greater than 2.5%                                                       water                                                        10               Lumps up to 8 mm in size                                                      dispersed in less than 11                                                     minutes when prepared                                                         using greater than 2.5%                                                       water                                                        11               Lumps up to 8 mm in size                                                      dispersed in less than 8                                                      minutes when prepared                                                         using greater than 1.0%                                                       water                                                        C1               Lumps up to 8 mm in size                                                      dispersed only partially                                                      within 60 minutes                                            C2               Lumps up to 8 mm in size                                                      did not disperse                                                              completely within 66                                                          minutes                                                      C3               Granules up to 1 mm in size                                                   took >20 minutes for                                                          dispersion                                                   ______________________________________                                    

EXAMPLE 13 Particle Size Analysis of the Formulations

A particle size analysis of the formulations of Examples 3 to 11 andComparative Example C3 was carried out using a Sympatec Helos laserdiffraction instrument operated according to the maker's instructions.

All measurements were carried out using, as measuring medium, distilledwater that had been pre-saturated with triazamate at the test roomtemperature and then filtered through a 0.2 μm cellulose nitratemembrane prior to use.

Details concerning the average triazamate particle size for Examples 3to 6 and Comparative Example C3 are provided in Table 4 below.

                  TABLE 4                                                         ______________________________________                                                      Average triaamate                                               EXAMPLE NO.   particle size/μm                                             ______________________________________                                        3             15.6                                                            4             11.0                                                            5             8.0                                                             6             5.9                                                             C3            19.6                                                            ______________________________________                                    

For Examples 7 to 11, the results are presented in graphical form, asfollows:

    ______________________________________                                               Example                                                                              FIG. NO.                                                        ______________________________________                                               7      see FIG. 1                                                             8      see FIG. 2                                                             9      see FIG. 3                                                             10     see FIG. 4                                                             11     see FIG. 5                                                      ______________________________________                                    

The graphs of FIGS. 1 to 5 were generated using a graphics softwarepackage sold under the Trade Mark "T-curve" which was available on aSperry Type3126-00 (Trade Mark) computer. The curves shown are "bestfits".

In each of FIGS. 1 to 5, two curves are shown which represent maximumparticle size of the smallest 50% and 90% of particles respectively.

The following points may be concluded from the Examples discussed above:

(i) The speed of dispersibility of the formulations in water isincreased when an anionic surfactant (e.g. Morwet D425 orPhenylsulphonate Ca) is used in the formulations--Compare Examples 1 and2 with Examples C1 and C2; and compare Examples 3 to 6 with Example C3.

(ii) The speed of dispersibility of the formulations in water isincreased the greater the amount of anionic surfactant used in theformulations--Compare Examples 3 to 6 which show the effect ofincreasing the amount of anionic surfactant (Morwet D425) in theformulations.

(iii) The average size of active ingredient (e.g. triazamate) particlesin the dispersed formulations decreases as the amount of anionicsurfactant in the formulations increases--Compare Examples 3 to 6.

(iv) The fineness of the precipitated triazamate particles and, hence,the speed of dispersibility of the formulations in water, is affected bythe quantity of water used in the processes of preparation of theformulations--see Examples 7 to 11 and FIGS. 1 to 5.

The following effects have also been noted:

(v) The use of an anionic surfactant in the process for the preparationof the formulations aids the solidification of the formulations.

(vi) The shape of the precipitated particles of active ingredient (e.g.triazamate) is dependent upon the nature of non-ionic surfactant used.

(vii) When the water dispersed formulations are used in the treatment ofpests, the effect against pests is comparable to equivalent emulsionconcentrates and/or suspension concentrates of the active ingredients.

I claim:
 1. A water dispersible solid formulation comprising:an activepesticide ingredient consisting essentially of of effective amount oftriazamate, having an average particle size by volume of less than about50 μm; a surfactant of non-ionic type selected from the group consistingof an alcohol and ester; a surfactant of an anionic type; and at least30 wt % of urea.
 2. A formulation as claimed in claim 1, wherein saidurea is complexed with said surfactant of non-ionic type.
 3. Aformulation as claimed in claim 1, including at least 50 wt % of urea.4. A formulation as claimed in claim 2, including 10-40 wt % of saidsurfactant of non-ionic type.
 5. A formulation as claimed in claim 1,including 4-30 wt % of said surfactant of anionic type.
 6. A formulationas claimed in claim 1, including 10-40 wt % of said active ingredient.7. A process of preparing a water dispersible solid formulationaccording to claim 1, the process comprising mixing together a meltconsisting essentially of the active ingredient and a surfactant of anon-ionic type, a surfactant of an anionic type and at least 30 wt % ofurea to obtain a mixture, and allowing the mixture to solidify.
 8. Aprocess as claimed in claim 7, including the steps of melting saidactive ingredient and subsequently allowing said active ingredient toprecipitate.
 9. A process as claimed in claim 7, wherein the process iscarried out in the presence of a minor amount of water.
 10. A method ofdelivering an active ingredient to a surface, the method comprisingapplying to the surface an aqueous dispersion of a water dispersiblesolid formulation as claimed in claim
 1. 11. A formulation as claimed inclaim 1, wherein the surfactant of the non-ionic type is selected fromeither a fatty or alkoxylated alcohol and ester.
 12. A formulation asclaimed in claim 1, wherein the surfactant of the anionic type isselected from the group consisting of an aldehyde condensate, analiphatic sulphate salt and an aromatic sulphonate salt.
 13. Aformulation as claimed in claim 12, wherein the aldehyde condensate is asulphonated condensate.
 14. A water dispersible solid formulationcomprising:a melt formed of an active crop protection ingredientconsisting essentially of an effective amount of triazamate having anaverage particle size by volume of less than about 50 μm, and asurfactant of a non-ionic type selected from the group consisting of analcohol and ester; a surfactant of an artionic type; and at least 30 wt% of urea.
 15. A formulation as claimed in claim 14, wherein the cropprotection ingredient is triazamate.
 16. A formulation as claimed inclaim 14, where the crop protection ingredient is selected from thegroup consisting of an insecticide, fungicide, acaricide, ovicide,nematocide, herbicide, plant growth regulator and a mixture of the same.17. A formulation as claimed in claim 14, wherein the surfactant of thenon-ionic type is selected from either a fatty or alkoxylated alcoholand ester.
 18. A formulation as claimed in claim 14, wherein thesurfactant of the anionic type is selected from the group consisting ofan aldehyde condensate, an aliphatic sulphate salt and an aromaticsulphonate salt.
 19. A formulation as claimed in claim 14, wherein thealdehyde condensate is a sulphonated condensate.